The entire disclosure of Japanese Patent Application No. 2000-144891 filed on May 17, 2000 including specification, claims, drawings and summary is incorporated herein by reference in its entirety.
1. Field of the Invention
The invention relates to an apparatus for semi-automating switching operations for a web offset printing press, and particularly to an apparatus for automatically actuating such devices successively by an operator pushing one or more buttons.
2. Description of Related Art
In a conventional art, when changing from a previous job to a next job in a web offset printing press, an operator has to operate each of the devices to operate the overall printing operation in a proper order. This takes a lot of time and is burdensome to the operator.
For example, when the previous job is finished, printing units are stopped to clean a blanket cylinder with a blanket. Then, the printing plates are exchanged, and further, an old web roll is changed to a new web roll. In order to prepare for the next job, various presetting operations, such as an adjustment of an open degree of an ink fountain key in accordance with a picture pattern of a new printing press, a control of a rotational amount of each ink fountain roll, a determination of an amount of dampening water to be su lied, and a setting of a folding machine
In the above described conventional art, when changing from the previous job to the next job, an operator has to activate each device in order. Thus, it takes a long time and a heavy burden is imposed on the operator.
In the present invention, an operator merely pushes three buttons to automatically actuate each device in order to solve the above problems.
Further, it is also an object of the present invention to reduce the cost by changing a sheet travel path manually by an operator before operating a second switch, and visually checking by the operator that a printing plate is correctly changed and that a sufficient amount of a web roll is stocked before pushing a third button.
To accomplish the above object, an apparatus for automating switching operations of a web offset printing press according to the present invention comprises web continuous supplement means for attaching a web of a new web roll to a web of an old web roll to supply the web successively, printing plate changing means for changing a printing plate supported on a plate cylinder, folding device status switching means for switching a folding device status in accordance with a folding variation of the next printing, and ink supplement means for reducing ink amount to a basic ink layer thickness distribution and overlapping an ink layer distribution, corresponding to the next printing, on the basic ink layer thickness distribution, wherein the apparatus for automating switching operations of a web offset printing press is characterized by further comprising a switch for changing from a previous printing to the next printing. Based on a first signal from the switch, the ink supplement means reduces the ink amount to the basic ink layer thickness distribution, and the web continuous supplement means replaces and connects the web rolls. Based on a second signal from the switch, the printing plate changing means and the folding device status switching means are activated, and based on a third signal from the switch, the ink supplement means is activated to overlap the ink layer thickness distribution in accordance with the next printing.